diff --git a/targetlibs/stm32f1/usb/usb_conf.h b/targetlibs/stm32f1/usb/usb_conf.h
index fa93fdc54..e7ef8a8eb 100644
--- a/targetlibs/stm32f1/usb/usb_conf.h
+++ b/targetlibs/stm32f1/usb/usb_conf.h
@@ -69,7 +69,7 @@
 /* IMR_MSK */
 /* mask defining which events has to be handled */
 /* by the device application software */
-#define IMR_MSK (CNTR_CTRM  | CNTR_SOFM  | CNTR_RESETM )
+#define IMR_MSK (CNTR_CTRM  | CNTR_ERRM  | CNTR_SOFM | CNTR_ESOFM | CNTR_RESETM )
 //#define IMR_MSK (CNTR_CTRM  | CNTR_WKUPM | CNTR_SUSPM | CNTR_ERRM  | CNTR_SOFM | CNTR_ESOFM | CNTR_RESETM )